I had few concerns about the answer provided
1. The authors of the paper 'propose' the mechanism; but I do not see much of the evidance presented in support of the mechanism. My objection is regarding the step of retro-Brook rearrangement. Under the reaction conditions used I can not understand how that step is thermodynamically feasible [as the driving force for brook rearrangement is higher Si-O bond energy over Si-C].
To me, intermediate 9 (according to the article) looks themodynamically more stable than 10 and 9 should be stable enough to get protonated.
2. Retro-Brook rearrangements I found in literature were all using some other catalyst which was coupling a thermodynamically favorable reaction to make the net :delta:G negative.
3. In the question posted, formation of the other isomer (11, in the article) was not mentioned which I thought could be important in guessing the mechanism.